tests: import-example: prefer angle syntax

Let's prefer to use angle bracket syntax rather than curly brace syntax
in our tests which create an ImportExample component.

Author: geneukum

tests/integration/components/import-example-test.js

@@ -8,14 +8,14 @@ module('Integration | Component | import example', function (hooks) {
 
   test('it renders a class import example', async function (assert) {
     await render(
-      hbs`{{import-example item='Application' package='@ember/application'}}`
+      hbs`<ImportExample @item='Application' @package='@ember/application'/>`
     );
     assert.dom('*').hasText("import Application from '@ember/application';");
   });
 
   test('it renders a function import example', async function (assert) {
     await render(
-      hbs`{{import-example item='{ uniqBy }' package='@ember/object/computed'}}`
+      hbs`<ImportExample @item='{ uniqBy }' @package='@ember/object/computed'/>`
     );
     assert.dom('*').hasText("import { uniqBy } from '@ember/object/computed';");
   });